Circuit breaker for spark distributors



JUY 6, 1937. A. A. MELAcHER ET AL. y2,085,817

CIRCUIT BREAKER FOR SPARK DISTRIBUTORS Filed Feb. 12. 195e Patented July6, 1937 UNITED STATES PATENT OFFICE CIRCUIT BREAKER Fon SPARKADISTRIBUTORS Alfred A. Melcher and Albert G. H. Yanderpoel, Los Angeles,Calif., assignors of one-fourth to James OLaverty and one-fourth toDavid E. Seward, yboth of. Los Angeles, Calif.

Application February 12, 1936, Serial No. 63,562

' 1o claims. (01.123-117) 'Letters Patent led October 7, `1935, SerialNo.

43,814 Patent No. 2,066,640 1937.

In our co-pending application, the position of the breaker arm withrespect to the timing cam is controlled by a shaft or rod mounted forrocking movement and movable lengthwise by means of a pin that traversesan inclined slot in the sleeve that surrounds the rod or shaft and itisthe prindated January 5,

cipal object of our present invention toeliminate the parts justmentioned and accomplish the same results by mounting the breaker arm ona rotary member that is arranged for movement on an axis that is offsetor eccentric with respect to the axis of the timing cam, thus materiallyreducing the number of operating parts of the device and providing aconstruction that is relatively simple and practical, inexpensive ofmanufacture and positive in operation.

A further object of our invention is, to provide simple and -efcientmeans for automatically regulating the time period of electrical dwellor contact of the breaker contacts and thereby reg-.

the primary circuit to correspond with the speed of the'gaseous fuelmixture passing through the carburetor of the internal combustionengine, with which the device is associated and the demands of theoutput.

In connection with the ignition systems of internal combustion engines,it will be understood that while the engine is running at low or, idlespeeds, a relatively short contact in the primary circuit producessufficient saturation of the coil without oversaturation and that whilethe engine is running at high speeds, alonger contact is necessary toproperly saturate the coil. Over.

Flg. 1.

saturation heats and burns out the coil and the contact points in thedistributor head and these objectionable results are eliminated wheremyy primary current vflowing through the primary winding and I. aroundthe core ofA the coil that magnetizes the core. Thus the core ismagnetizd when the circuit is closed and demagnetized when Acoil for aconstant milliampere the .circuit is open. The spark for igniting thegaseous fuel charges occurs when the coil is demagnetized by opening theprimary circuit.

To produce a strong spark, the core of the coil must be completelysaturated or magnetized and in order to do this, the primary circuitmust be closed'by the contact points for a suflicient length of time byreason of the fact that the coil will not become magnetizedinstantaneously. A certain period of time is required. This being true,it will be seenthatthe spark or secondary current will grow weaker asthe speed of the engine increases because 'the `speed of the cam thatoperates the circuit breaker correspondingly increases, wh-ich shortensthe time of contact or dwell of the contact points of the primarycircuit. lIt is oneof the purposes of our invention, to providefsimpleand eicient means that is automaticallyv actuated, preferably by thevelocity of .the flow -ofgaseous mixture through the .car-

buretor into the intake manifold, for controlling the periods ofcOntaCtor the time of dwell of the contacts iii-the".- primary circuit,corresponding with the. engine speeds, in order to bring about thepropertiming ofthe saturation of the core of the coil. *I

With the 'foregoing and other objects in view our invention consists incertain novel featuresA of construction and arrangements of parts thatwill bev hereinafter more fully described and claimed andv illustratedin the accompanying drawing in wliichz;

Fig. 1 is a top vplan view of a circuit breaker and spark 'distributorf'constructed in accordance --with our invention and showing in sectionthe Fig. 4 is aplan view ofthe eccentrically mounted breaker armcarrying plate and the disc or plate upon which the same is mounted.

Referringby numerals to the accompanying drawing which illustrates apreferred embodiment of our invention, i0 designates a conventionaldistributor head in which is mounted for rotation the usual axiallydisposed shaft I I carrying the timing cam I2. Y Suitably secured withinthe recessed upper portion of head I is a disc or plate I3 and thecentral portion of this disc or plate is pressed downwardly to form aneccentrically arranged circular recess I l.

An inwardly presented iiange I5 surrounds the lower portion of thisrecess.

ranged opening and surrounding the latter, is a` depending ange that iscarried by the inner race I'I. As a result of this construction andparticularly the provision of the eccentric recess I4, the antifrictionbearing and the depending flange 23 of plate I9 are eccentricallyarranged with respect to the axis of shaft Ii that carries the timv ingcam.

Pivotally mounted in the conventional manner on plate I3, is a breakerarm 2I of the usual con- `struction and which carries at its free end acontact point 22.

Carried by the intermediate portion of the breaker arm 2 I is a block orshoe 23 that is adapted to be engaged by the high points of the timingcam I2.

Contact 22 is adapted to engage a fixed contact 24, the latter beingcarried by a screw 25 that is seated in a bracket 26 and which screw issecured in its adjusted position by means of a lock nut 21. Bracket 26is carried by plate I3.

Pivotally connected to plate I3 adjacent the pivoted end of the breakerarm 2I, is one end of a link 28, the same extending substantiallytangential from said plate through a housing 29 that -s connected to thebreaker head I0 and the outer end of this link is pivotally connected tothe cenlter of a diaphragm 30. The edge of this diaphragm is clampedbetween the divided parts of a housing 3-I and one of the parts of saidhousing having a tubular extension 32. The outer end of this extension32 is closed and extending through said closed end and communicatingwith the chamber in the extension 32 is a tubular duct 33 that leads tothe chamber within a conventional carburetor 34, preferably at a pointbetween the throttle valve T andi the venturi V.

Interposed between the central portion of diaphragm 30 and the outer endof the tubular member 32, is an expansive coil spring 35 whichyieldingly resists the movement of the diaphragm toward the side ofthehousing 31| having the tubular extension 32.

That portion of tube 33 that extends into the carburetor functions as aPitot tube to control the pressure exerted on the diaphragm 30. In someinstances, to produce the desired results,.tube 33 may be extendeddirectly into the venturi or into the carburetor at or -near the pointof highest velocity flow of the gaseous mixture therethrough.

jeous mixture passing through the carburetor is not strong enough toovercome the-tension of Fig; 1.

Under such conditions plate or disc I5 supported on the antifrictionbearings in the eccentric recess I4 in disc I 3, occupies a position sothat when contact 22 carried by the free end of said breaker arm isinengagement with adjustable contact 24, the face of shoe 23 is spaced avery slight distance away from the central portion of one of the angularfaces of cam i2.

Under such conditions the time period of engagement between the contacts22 and 24 is comparatively short, but even so such comparatively shortdwell of the contacts is sufficient to permit the flow of sufficientcurrent through the contact and other connections to bring about thedesired degree of saturation of the coil.

As the cam I2 moves a short distance, one of the faces thereof willengage shoe 23 and as a result of such engagement breaker arm 2I will beswungAoutwar'dly away from the cam, thus separating the contacts 22 and24 and the flow of current to the coil ceases.

Thus under slow or idling speed there is a relatively short period ofdwell or contact between the contacts 22 and 24 and a much longer timeperiod of separation between such contacts and as a result the coil issaturated for only a short -time or while the contacts 22 and 24 areclosed.

As, the throttle is opened to increase the speed of the engine, thecorresponding increase in the velocity of the gaseous fuel mixture fromthe carburetor to the intake manifold produces suction through tube 33and this suction is exerted upon diaphragm 30 to draw the same towardthe side of housing 3| having the extension 32 and the movement thusimparted to said diaphragm is imparted by link 28 to the disc or plateI3, such movement causing partial rotation of said disc or plate in theeccentric recess I4.

Due to the fact that plate I3 carrying the breaker arm 3| iseccentrically mounted with respect to the axis of the cam I2, thebreaker arm will be carried into a position whereby the face of contactshoe 23 occupies a position a greater distance away from the axis of theshaft carrying the cam with the result that the high portions of the camonly engage the face of shoe 23 for shorter periods of time than underthe'conditions previously described while the engine is idling and suchaction increases or lengthens the dwell or periods of contact betweenthe contacts 22 and 2`4, thus correspondingly lengthening the timeperiods of saturation of the coil and which result is desirableforhigher engine speeds.

Thus when the engine is run at its maximum or highest speed, the swellor time period of contact between the contacts 22 and 24 are of longestduration and this brings about the desired degree of saturation of thecoil with the contact point.

As the speed -oi the engine decreases its idling speed, l the suctionproduced through the carburetor correspondingly decreases and diaof thebreaker arm and particularly the contact shoe 23 with respect to theaxis of the cam and `the periods of dwell or contact between thecontacts 22 and 24 will be correspondingly increased so as to bringabout the desired degreefof lsaturation of the coil during thedecreasing and idle speed of the engine. Thus it will be seenV that inour improved circuit breaker, the mounting of the contact arm on arotary member having an axis offset. or eccentric with respect to theaxis of the shaft carrying the cam provides simple and eiicient meansfor increasing or decreasing the gap in the ignition circuit accordingto the speed of the engine and the demands of the coil fora constantmilliampere output and the velocity of the gaseous mixture owing fromthe carburetor to the intake manifold automatically controlling theposition of the breaker arm and the contact shoe carried therebyrelative to the cam that operates said breaker arm.

The use of our improved circuit breaker enables a higher voltage coil tobe used in the ignition system and such lcondition is especiallydesirable and advantageous inasmuch as it produces the desired results,particularly at vhigh engine speeds.

Our improved form of circuit breaker may be advantageously employed inconnection with the present forms of automatic timers and ignitiondevices by merely substituting our improved form of breaker arm carryingring or plate and its supporting plate, for the corresponding parts nowutilized in standard forms of circuit breakers and spark distributors.

The eccentrically mounted plate `that carries the breaker arm islmounted so that when the engine speeds up so as to impart movement tosaid plate, such movement is in the opposite direction from that of therotary movement of the shaft carrying the cam and as a result of thismovement, the spark is automatically advanced and such advance isproportionate or in keeping with the engine speed.

As illustrated by the arrow and legend ADV. in Fig. 1, the rotarymovement of the plate I9 when actuated as a result of increased enginespeed, is anti-clockwise and at all times the shaft Il, carrying timingcam l2, rotates clockwise as indicated by the arrows Figs. 1 and 2. Whenthe engine speed decreases, the rotary movement of the plate I9 isclockwise as indicated by the arrow and legend RET. in Fig. 2.

Obviously as the breaker arm carrying plate returns to its normalposition it moves in the same direction with that of the cam and thespark is correspondingly retarded as the engine slows down.

In order to regulate the tension of spring 35, a rod 36 is screw-seatedin the tting that connects tube 33 to the tubular extension 32 of thediaphragm housing 3|, and the inner end of this screw rod carries a disk31 that provides a bearing for the adjacent end of spring 35.

Thus the action of the diaphragm may be read- A ily controlled.

As a result of our improved construction, it is not necessary to employthe conventional Weights Y utilized in connection with the shaft of thetimmounted so that the distance between its axis spark due to thecorrect period of dwell oi contact to bring about the proper degree ofcoil saturation. l

Thus it will be seen that we have provided a circuit breaker for sparkdistributors that is relatively simple in construction, inexpensive ofmanufacture and very eiective in performing the functions for which itis intended.

It will be understood that minor changes in the size, form andconstruction of the various parts of our improved circuit breaker forspark distributors may be made and substituted for those herein shownand described without departing from the spirit of the invention, thescope of which is set forth in the appended claims.

We claim as our invention:

1. In a circuit breaker for spark distributors including a cam, acontact carrying' breaker arm and a relatively fixed contact, a membermounted for rotary movement on an axis that is eccentric relative to theaxis of the cam, said rotary member carrying said breaker arm and saidrelatively xed contact and automatically operating means controlled bythe velocity flow of the gas air mixture through the carburetor withwhich the circuit breaker is associated for imparting movementto saidrotatably mounted member.

2. In a circuit breaker f or spark distributors including a rotary cam,a member mounted for rotary movement on an axis that is eccentric to theaxis of said cam, a contact carrying breaker arm pivotally mounted onsaid member, a relatively xed contact carried by said member andautomatically operating means controlled by the velocity flow of the gasair mixture through the carburetor with which the circuit breaker isassociated for imparting movement to said member to change the positionof said contact carrying breaker arm and the relatively xed contact withrespect to said cam.

3. In a circuit breaker for spark distributors including a rotary cam, amember mounted for rotary movement on an axis that is eccentric to theaxis of the cam, a breaker arm pivotally' mounted on said'member, a shoecarried by said breaker arm, which shoe is adapted to be engaged by thecam during its rotary movement, a contact carried by said breaker arm, arelatively xed -contact mounted on `said member and radapted to beengaged by the contact carried by the breaker arm and automaticallyoperating means actuated and controlled by the velocity oW of the gasair mixture through the carburetor with which the circuit breakerisasso- `ciated for imparting movement to said member so as to changethe position of the parts carried thereby with respect to said cam.

4. In a circuit breaker for spark distributors including a rotary cam,of a member mounted for rotation adjacent said cam, the axis of which vmember is eccentric with respect to the axis of the cam, a breakerarmpivotally mounted on said rotatably mounted member, a shoe carried bysaid breaker arm, which shoe is adapted to be engaged by said cam, acontact carried by the breaker arm, a relatively fixed contact that isadapted to be engaged by the contact carried by said breaker arm, andautomatically operating means actuated and controlled by the velocity owof the gas air mixture through the car.- buretor with which the circuitbreaker is associated for Iimparting'rotary vmovement to saideccentrically arranged member.

5. In a circuit breaker for spark distributors including a rotary cam, amember mounted for rotation adjacent said cam and having an axis that iseccentric with respect to the` axis of said cam, a breaker arm pivotallymounted on said member, a shoe carried by said breaker arm with whichsaid cam is adapted to engage, a contact carried by said breaker arm, arelatively xed contact carried by said member with which the contactcarried by the breaker arm is adapted to engage and means actuated andcontrolled by the velocity of the gas-air mixture through the carburetorwith which the circuit breaker is associated for'imparting movement tosaid member to change the positions of the parts carried thereby withrespect to the cam so as to increase or decrease the periods of contactor dwell between the contact carried by the breaker arm and therelatively stationary contact.'

6. In a circuit breaker for spark distributors including a rotary cam, amember mounted for rotation adjacent said cam and having an axis that iseccentric with respect to the axis of said cam, a breaker arm pivotallymounted on said member, a shoe carried by said breaker arm with whichsaid cam is adapted to engage, a contact `carried by said breaker arm, arelatively xed contact carried by said member with which the contactcarried by the breaker arm is adapted to engage and means controlled bythe speed of the engine with which the circuit breaker is associated forimparting movement to said member to change the positions of the partscarried thereby with respect to the cam so as to increase or decreasethe periods of contact or dweil between the'contact carried by thebreaker arm and the relatively stationary contact.

'1. The combination with a -spark distributor head and the rotary camassociated therewith, of a member mounted for rotation on said head andhaving an axis that is eccentric relative to the axisV of said cam,a'breaker armpivotally mounted on said member, a shoe carried by saidbreaker arm and adapted to be engaged by said cam, a contact carried bysaidbreaker arm, a relatively iixed contact carried by said member andadaptedto be engaged by the contact carried by the breaker arm and meansactuated and controlled by the now of gas-air mixture through isassociatedior imparting movement to `said member to change the positionthereof and the aosaeir i positions oi the parts carried. thereby withrespect to said cam.

8. The combination with a spark distributor head and the rotary camassociated therewith, of a member mounted for rotary movement on saidhead, the axis of which member is eccentric with respect to then axis ofthe cam, a breaker arm pivotally carried by said rotatably mountedmember, a shoe carried by said breaker arm and adapted to be engaged bysaid cam, a contact carried byv said breaker arm, arelatively stationarycontact carried by said member and adapted to be engaged by the contactcarried by said breaker arm and automatically operating means actuatedand controlled by the velocity ow of the gas air mixture through thecarburetor with which the spark distributor is associated forimpartingmovement to said eccentrically mounted member.

9. The combination with a spark distributor head and the rotary camassociated therewith, of a member mounted for rotary movement on saidhead, the axis of which member is eccentric with respect to the axis ofthe cam, a breaker arm pivotally carried by said rotatably mountedmember, a shoe carried by said breaker arm. and adapted to be engaged bysaid cam, a contact carried by said breaker arm, a relatively stationarycontact carried by said member and adapted to be engaged by the contactcarried by said breaker arm and automatically operating means actuatedand controlled by the speed of the engine with which the circuit breakerpis associated for imparting rotary movement to said eccentricallymounted member.

10. In a circuit breaker for spark distributors, including a rotary cam,a member surrounding said cam and mounted for rotation on an axis thatis eccentric with nespect to the axis of said cam, a breaker armpivotally mounted on said member, a shoe carried by said breaker armwith which said cam is adapted to engage, a contact carried by saidbreaker arm, a relatively xed contact carried by said breaker arm withwhich the contact carried by the breaker arm is adapted to engage, meanslocated adjacent the distributor for converting vacuum suction intomovement, and means connecting said converting means with theeccentrically mounted breaker arm car` vrying member.

ALFRED A. MIELCHER. ALBERT G. H. VANDERPOEL. l

